Patent GB-438959-A (GB)
Title: Improvements in or relating to absorption refrigerating apparatus
IPC: F25B17/00
Filed: 1934-04-24
Abstract: 438,959. Refrigerating. ELECTROLUX, Ltd., Luton, Bedfordshire.-(Assignees of Platen-Munters Refrigerating System Aktiebolag; 2, Norrmalmstorg, Stockholm) April 24, 1934, No. 12372. Convention date, April 25, 1933. [Class 29] Absorption systems.-In an intermittent system of the kind described in Specification 431,267, the equalizing vessel is arranged in liquid communication with the generator so that liquid may flow therefrom to the generator during generation independently of, and in addition to, that passing from the storage vessel. The system may comprise a generator 10 having a central flue heated, e.g. by a gas burner and provided with a pumping-coil 20, an analyzer 14 to which is connected an equalizing vessel 17, heat-exchangers 15, 33, storage vessel and absorber 13, rectifier 16, condenser 11, and evaporator 12. In use, the apparatus is filled to the level I with a solution of, e.g. ammonia in water and upon lifting of the burner solution is withdrawn from the analyzer by the pump 20 and discharged into the generator through the riser pipe 21. The vapour evolved in the generator passes through the pipe 22 and the liquid seal 23 to the analyzer and thence through the duct 24 and forces the liquid from the limb 25 into the limb 26 of a U-tube eventually bubbling through the liquid to the condenser 11. The condensate flows into a jacket around the rectifier 16 and thence up the pipe 30 to the evaporator 12. During this time, the generator is replenished with strong liquor from the equalizing vessel and the analyzer through the pipes 48, 61, while weak liquor flows through the pipe 31 and the heat-exchangers 15, 33 to the pipe 34. From the latter pipe a part of the weak liquor rises in the pipe 36 to the level Ib, while the remainder passes into the storage vessel and promotes flow therefrom to the analyzer. Heating of the generator continues until the liquid in the equalizing vessel and the analyzer falls to the level Ic when the liquid seal 43 in the pipe 42 is broken and vapour flows through the pipe 39 to the jacket 40 around the feeler 41 of a thermostat bellows 45 which closes a valve 47 in the gas supply pipe to the generator burner. Closure of the valve 47 effects a rapid fall of pressure in the analyser and the initiation of vaporization in the evaporator 12. Liquor flowing from the storage vessel 13 to the analyzer is replaced by liquor from the pipe 36 thus permitting vapour to pass from the evaporator through the pipe 34 to the vessel 13 and inducing a flow of weak liquor from the generator to the vessel. The analyzer, equalizing vessel, and generator are thus refilled with strong liquor from the vessel 13 in readiness for another period of generation. Upon completion of evaporation, the temperature of the evaporator rises and effects, through a thermostat bellows 50, opening of a second valve 52 in the gas supply pipe thus permitting relighting of the generator burner by the usual pilot jet, since the valve 47 has in the meantime reopened. In order to produce a continuous cooling effect, a secondary system is associated with the evaporator 12 comprising a jacket 55 provided with a condenser-evaporator coil 60 containing a volatile liquid and connected to a vessel 57 filled with a solid absorber for a secondary refrigerant and having condenserevaporator coils 58, 59, the evaporator parts of the coils 58, 60 being disposed in the space to be cooled. The coil 59 is provided to transfer the heat of absorption from the vessel 57 to the atmosphere. In a modification, the equalizing vessel 17, Fig. 2, communicates through a liquid-sealed tube 64 with a pipe 62 connected between the generator 10 and a vertical pipe 65, the upper part of which constitutes a rectifier 16 which communicates through an aperture 66 with a jacket 29 connected to a finned-tube condenser-absorber 11. The condenser-absorber is connected by a tube 69 having an orifice 72 at its lower end with a weak-liquor collecting vessel 18. The apparatus is initially filled to the level I with, e.g. a solution of ammonia in water and upon heating the generator 10 vapour passes through the liquor in the pipes 62, 65 to the condenser, the condensate collecting in the jacket 29 and passing through the seal 67, pipe 30, and seal 70 to the evaporator 12. The collection of refrigerant in the evaporator results in a fall of the liquid level in the pipe 65 and strong liquor flows through the pipe 64 from the equalizing vessel 17 to the pipe 62 thus assisting in the rectification of the vapour leaving the generator. Circulation of liquor between the vessel 74 and the generator through the heatexchanger 33 is effected by the generator pumping coil 20. When the liquid reaches the level II, the heat supply to the generator is cut off, e.g. thermostatically, and the consequent cooling of the apparatus permits vaporization of the refrigerant in the evaporator and the flow of weak liquor and vapour through the pipe 69 into the condenser which row acts as an absorber, the strong liquor passing through the aperture 66 into pipe 65 and thus raising the liquid to the level I. During absorption, weak liquor is sacked into the vessel 18 from the vessel 74. In another arrangement, independent condenser and absorber tubes are provided.